The invention relates to a method and apparatus for connecting high data rate telephone calls over conventional low data rate telephone lines.
Communication network subscribers have the option of subscribing to plain old telephone service (POTS) or high data rate service, e.g. ISDN (integrated services digital network). POTS is suitable for voice communication, low data rate data communications, and computer transmission via modem and facsimile. ISDN service is suitable for high data rate data communications, e.g. high data rate computer transmissions and video.
To have access to the greater data rate of ISDN service, a subscriber must make arrangements before he needs the high data rate to have the ISDN service connected. In many situations, however, the individual does not have the option to have ISDN service connected, e.g. when calling from a public area. ISDN service has the additional disadvantages that the subscriber (a) has to pay to have the ISDN line installed and (b) has to pay a monthly fee for the ISDN connection in excess of that for a POTS connection.
The invention provides method and apparatus by which a telephone subscriber can obtain the benefits of high data rate communication using low data rate (baseband) POTS telephone lines. Individuals using the invention will be able to take advantage of higher data rate communication on demand, from any location with multiple POTS lines installed, and without being charged for connection to ISDN service.
In general, in one aspect, the invention features a broadband port for connection to a broadband device or broadband communication line; baseband ports for connection to beseband communication lines; a controller for integrating or reassembling baseband data streams accepted at said baseband ports into a broadband data stream for transmission at said broadband port, said accepted baseband data including message data for conveyance at said broadband port and control data describing an interrelationship among the message data received on said baseband ports, and for demultiplexing or disassembling a broadband data stream received at the broadband port into a plurality of baseband data streams for transmission at the baseband ports.
The advantages of the invention include the following. A broadband call can be placed to or from a location where no broadband line is available. For instance, in an airport, a user could use two or four adjoining pay stations to connect a broadband call.